Catalyst for olefin polymerization and process for producing olefin polymer with the catalyst

ABSTRACT

A catalyst which comprises a compound of a transition metal in Groups 8 to 10 of the Periodic Table having a nitrogenous tridentate ligand, a clay, clay minteral, or lamellar ion-exchanging compound, an organosilane compound, and organoaluminum compound, etc.; and a process for producing a polyolefin with the catalyst. The catalyst is highly active, does not adhere to reactor walls, and can give a polyolefin excellent in powder morphology. Consequently, a polyolefin (especially polyethylene) can be industrially advantageously produced.

TECHNICAL FIELD

The present invention relates to catalysts for olefin polymerization andto a method of using the catalysts for producing.olefin polymers. Moreprecisely, the invention relates to catalysts for olefin polymerization,with which polyolefins, especially polyethylenes are efficientlyproduced on an industrial scale, and relates to a method of using thecatalysts for producing olefin polymers.

BACKGROUND ART

At present, Ziegler catalysts and metallocene catalysts are much usedfor olefin polymerization, and they comprise, as the essential catalystcomponent, a compound of a metal element belonging to Group 4 of thePeriodic Table, such as titanium, zirconium, etc.

On the other hand, recently, novel catalyst systems that differ from theabove have been developed, and they comprise a complex of a metalbelonging to Groups 8 to 10 of the Periodic Table, such as typicallynickel or palladium. Heretofore, nickel complexes have been known asoligomerization catalysts for olefins, but it has been said that theyare unsuitable to polymer production.

Regarding the catalyst systems comprising such a nickel or palladiumcomplex, some techniques have been proposed, including, for example, (1)a method of using a catalyst with an Ni(0) complex coordinated with anadduct of quinone and a tertiary phosphine for ethylene polymerization(Japanese Patent Publication No. 1796/1993); (2) a catalyst systemcomprising an Ni(0) complex, an adduct of maleic anhydride and atertiary phosphine, a phosphorylide, and an organoaluminium compound(Japanese Patent Laid-Open No. 203106/1986); (3) a catalyst systemcomprising an Ni(0) or Ni(II) complex and an iminophospholane compound(Japanese Patent Laid-Open No. 115311/1991); (4) a method of using aborate complex of a metal of Groups 8 to 10 (Fe, Co, Ni, Ru, Rh, Pd, Os,Ir, Pt) coordinated with a cis-type chelate ligand for ethylenepolymerization (Japanese Patent Laid-Open No. 227608/1992); (5) acatalyst system comprising an Ni(0) complex, an adduct of an imide and atertiary phosphine, and a phosphine oxide (Japanese Patent Laid-Open No.122721/1994); (6) a catalyst system comprising a combination of aPd(II):BF₄ ⁻ complex and methylaluminoxane (Japanese Patent Laid-OpenNo. 82314/1995); (7) a catalyst system comprising an Ni(II) complex, animinophospholane compound and an organoaluminium compound (JapanesePatent Laid-Open No. 277610/1991); (8) a catalyst system comprising anNi(0) or Ni(II) complex and an iminophospholane compound having a bulkysubstituent (Japanese Patent Laid-Open No. 25932/1995); (9) a catalystsystem comprising a combination of an Ni(II):phosphorus:oxygen chelatecomplex and a linear or cyclic aluminium compound (Japanese PatentLaid-Open No. 14217/1989), etc.

However, the ethylene polymerization method (1) is defective in that itrequires an extremely high reaction pressure (for example, 100 kg/cm²)and the catalyst activity to give polyethylene therein is extremely low(about 6 kg/g-Ni·hr). The catalyst system (2) is also defective in thatit is for high-pressure ethylene reaction and it is complicated ascomprising many different components. In addition, its activity isextremely low (about 1 kg/g-Ni·hr or less). The catalyst system (3)could be effective even under low reaction pressure, but its activity isextremely low (about 1 kg/g-Ni·hr or less). In the ethylenepolymerization method (4), the catalyst activity is extremely low (about0.1 kg/g-Ni·hr or less). The activity of the catalyst system (5) is low(about 5 kg/g-Ni·hr). Though comprising a cationic complex, the catalystsystem (6) requires expensive methylaluminoxane for expressing itsactivity. In addition, its activity is low (about 3 kg/g-Ni·hr or less).The activity of the catalyst systems (7) and (8) is extremely low (about5 kg/g-Ni·hr or less). The catalyst system (9) contains a linear orcyclic organoaluminoxane that serves as a promoter. However, theorganoaluminoxane is produced through reaction of a trialkylaluminium ordialkylaluminium monochloride with water, and only methylaluminoxane isdescribed in the examples. No description relating to alow-molecular-weight linear or cyclic organoaluminiumoxy compound isgiven in the specification. In addition, the system requires expensivemethylaluminoxane. Still another drawback of the system is that itrequires high reaction pressure, correlating to its activity, but itsactivity is low (for example, about 20 kg/g-Ni·hr or less under areaction pressure of 30 kg/cm²G).

Recently, a catalyst system that comprises a combination of a complex ofa metal of Groups 8 to 10, typically such as nickel or palladium,coordinated with a nitrogen-containing ligand such as a diimine or thelike, and an organoaluminium compound such as methylaluminoxane (MAO) orthe like, or comprises the nitrogen-containing ligand complex combinedwith an anion species of BF₄ ⁻, PF₆ ⁻, SbF₆ ⁻ or BAF⁻[tetrakis(3,5-bistrifluoromethylphenyl)borate] has been disclosed(International Patent Laid-Open No. 96/23010). For example, disclosed isa catalyst system comprising a compound of a formula [1]:

wherein R¹⁰ and R¹³ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or an aromatic grouphaving from 7 to 20 carbon atoms in total and having a hydrocarbon groupon its ring; R¹¹ and R¹² each independently represent a hydrogen atom,or a hydrocarbon group having from 1 to 20 carbon atoms; R¹¹ and R¹² maybe bonded to each other to form a ring; X and Y each independentlyrepresent a hydrogen atom, or a hydrocarbon group having from 1 to 20carbon atoms; M represents a transition metal of Groups 8 to 10 of thePeriodic Table.

The catalyst system has the advantage of extremely high activity inethylene polymerization, as compared with the catalyst systems mentionedabove, but can be used only at low temperatures. In addition, themolecular weight of the polymers produced with it is low. Therefore, thecatalyst system is not as yet practicable.

Further recently, a catalyst system comprising a nitrogen-containingtridentate ligand complex with iron or cobalt has been disclosed(Brookhart et al., J. Am. Chem. Soc., 1998, 4049; Gibson et al., Chem.Commun., 1998, 849). For example, it includes a compound of a formula[2]:

wherein X and Y each independently represent a hydrogen atom, a halogenatom, or a hydrocarbon group having f rom 1 to 20 carbon atoms; Mrepresents a transition metal of Groups 8 to 10 of the Periodic Table.

The catalyst system has the advantage of extremely high activity inethylene polymerization (about 400 kg/g-Ni·hr), as compared with theconventional Group 8 to 10 transition metal catalysts:mentioned above.However, in order to fully express its activity, it requires a largeamount of an alumininoxane, especially methylaluminoxane.Methylaluminoxane is expensive, and, in addition, it is difficult tohandle, its storage stability is poor, and it is extremely dangerous.Aluminoxanes must be produced through reaction of a trialkylaluminium ordialkylaluminium monochloride with water, and the reaction efficiencyfor producing them is low. In addition, the catalyst residue must beremoved from the polymers produced. Furthermore, still another problemwith the polymerization method of using such an aluminoxane is that thepolymers produced often adhere to reactor walls and will be a bar tosafe driving of production equipment.

On the other hand, a method of olefin polymerization with a catalystthat comprises one or both of the above-mentioned transition metalcompound and aluminoxane carried on an inorganic oxide such as silica,alumina or the like, has been proposed (Japanese Patent Laid-Open Nos.108610/1986, 135408/1985, 296008/1986, 74412/1991, 74415/1991,272713/1997, etc.). Also proposed is a method of olefin polymerizationwith a catalyst that comprises one or both of the transition metalcompound and the organoaluminium compound carried on an inorganic oxidesuch as silica, alumina or the like, or on an organic substance(Japanese Patent Laid-Open Nos. 101303/1989, 207303/1989, 234709/1991,234710/1991, International Patent Publication No. 501869/1991, etc.).Still proposed is a method of using clay minerals for the catalystcomponent (Japanese Patent Laid-Open No. 301917/1993, etc.). However,for pretreatment of clay minerals, organoaluminium compounds areindispensable. Further, expensive and dangerous trimethylaluminium onlyis exemplified as the preferred agent for the treatment. Moreover, allthe proposed methods are still defective in that the catalyst activityper aluminium therein is low and the products contain a large amount ofcatalyst residues. Still another drawback of the methods is that thepolymers produced are amorphous and their powder morphology is not good.

The present invention relates to catalysts for olefin polymerization andto a method of using the catalysts for producing olefin polymers. Moreprecisely, its object is to provide catalysts for olefin polymerizationand a method of using the catalysts for producing olefin polymers, ofwhich the advantages are that the catalysts do not requiremethylaluminoxane to be derived from expensive trialkylaluminiums,removing catalyst residues from the polymers produced is unnecessary,the amount of the organoaluminium compound to be used is greatlyreduced, and olefin polymers, especially polyethylenes are efficientlyproduced on an industrial scale.

DISCLOSURE OF THE INVENTION

We, the present inventors have assiduously studied so as to attain theobject as above, and, as a result, have found that the object can beattained by polymerizing olefins, especially ethylene, in the presenceof a catalyst which comprises a transition metal compound of Groups 8 to10 of the Periodic Table having a specific structure, any of clay, aclay mineral or an ion-exchanging layered compound, and an organosilanecompound. On the basis of this finding, we have completed the presentinvention.

Specifically, the invention includes the first and second aspects as inthe following description, both providing catalysts for olefinpolymerization and a method of using the catalysts for producing olefinpolymers.

[First Aspect of the Invention]

1. A catalyst for olefin polymerization, comprising (A) a transitionmetal compound of the following general formula (I-I), which has anitrogen-containing tridentate ligand and of which the transition metalis of Groups 8 to 10 of the Periodic Table, (B) clay, a clay mineral oran ion-exchanging layered compound, (C) an organosilane compound, (D) anorganoaluminium compound and/or (E) an alkylating agent:

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent ahydrogen atom, a hydrocarbon group having from 1 to 20 carbon atoms, ora cycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal; X represents a halogen atom; Y represents a hydrogen atom, ahalogen atom, or a hydrocarbon group having from 1 to 20 carbon atoms; Zrepresents a nitrogen-containing functional group.

2. The catalyst for olefin polymerization of above 1, in which Z informula (I-I) is represented by the following general formula (I-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or a cycloaromatic hydrocarbongroup having from 7 to 20 carbon atoms in total; n represents 0 or anatural number.

3. The catalyst for olefin polymerization of above 1, in which Z informula (I-I) is represented by the following general formula (I-III):

wherein R⁷, R⁸ and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total, and thesemay be bonded to each other to form a ring; n represents 0 or a naturalnumber.

4. The catalyst for olefin polymerization of any of above 1 to 3, inwhich the transition metal of Groups 8 to 10 of the Periodic Table isiron or cobalt.

5. The catalyst for olefin polymerization of any of above 1 to 4, inwhich (B) is a phyllosilicate.

6. The catalyst for olefin polymerization of any of above 1 to 4, inwhich (B) is montmorillonite.

7. The catalyst for olefin polymerization of any of above 1 to 6, inwhich (C) is an organosilane compound having at least one alkyl groupdirectly bonded to the silicon atom.

8. The catalyst for olefin polymerization of any of above 1 to 7, inwhich (E) is a trialkylaluminium compound.

9. A method for producing olefin polymers, which comprises polymerizingolefins in the presence of the catalyst for olefin polymerization of anyof above 1 to 8.

10. The method for producing olefin polymers of above 9, in which theolefin is ethylene.

[Second Aspect of the Invention]

1. A catalyst for olefin polymerization, comprising (A) a transitionmetal compound which has a nitrogen-containing tridentate ligand and ofwhich the transition metal is of Groups 8 to 10 of the Periodic Table,(B) clay, a clay mineral or an ion-exchanging layered compound and (C)an organosilane compound.

2. The catalyst for olefin polymerization of above 1, in which thetransition metal compound (A) is represented by the following generalformula (II-I)

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent ahydrogen atom, a hydrocarbon group having from 1 to 20 carbon atoms, ora cycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal; X and Y each independently represent a hydrogen atom, or ahydrocarbon group having from 1 to 20 carbon atoms; Z represents anitrogen-containing functional group.

3. The catalyst for olefin polymerization of above 2, in which Z informula (II-I) is represented by the following general formula (II-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or a cycloaromatic hydrocarbongroup having from 7 to 20 carbon atoms in total; n represents 0 or anatural number.

4. The catalyst for olefin polymerization of above 2, in which Z informula (II-I) is represented by the following general formula (II-III):

wherein R⁷, R⁸ and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total, and thesemay be bonded to each other to form a ring; n represents 0 or a naturalnumber.

5. The catalyst for olefin polymerization of any of above 1 to 4, inwhich the transition metal of Groups 8 to 10 of the Periodic Table isiron or cobalt.

6. The catalyst for olefin polymerization of any of above 1 to 5, inwhich (B) is a phyllosilicate.

7. The catalyst for olefin polymerization of any of above 1 to 5, inwhich (B) is montmorillonite.

8. A method for producing olefin polymers, which comprises polymerizingolefins in the presence of the catalyst for olefin polymerization of anyof above 1 to 7.

9. The method for producing olefin polymers of above 8, in which theolefin is ethylene.

BEST MODES OF CARRYING OUT THE INVENTION

The first and second aspects of the invention are described below withreference to their embodiments.

[First Aspect of the Invention]

As so mentioned above, the catalyst for olefin polymerization of thefirst aspect of the invention (in this section, the first aspect of theinvention will be simply referred to as “the invention”) comprises (A) atransition metal compound of the above-mentioned formula (I), which hasa nitrogen-containing tridentate ligand and of which the transitionmetal is of Groups 8 to 10 of the Periodic Table, (B) clay, a claymineral or an ion-exchanging layered compound, (C) an organosilanecompound, (D) an organoaluminium compound and/or (E) an alkylatingagent. In the method for producing olefin polymers of the invention, theolefin polymerization catalyst is used for polymerizing olefins.

The catalyst for olefin polymerization and the method for producingolefin polymers of the first aspect of the invention are described indetail hereinunder.

[1] Catalyst for Olefin Polymerization

(1) Transition Metal Compound (A)

The transition metal compound (A) for use in the invention, which has anitrogen-containing tridentate ligand and of which the transition metalis of Groups 8 to 10 of the Periodic Table, is represented by thefollowing general formula (I-I):

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent ahydrogen atom, a hydrocarbon group having from 1 to 20 carbon atoms, ora cycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal; X represents a halogen atom; Y represents a hydrogen atom, ahalogen atom, or a hydrocarbon group having from 1 to 20 carbon atoms; Zrepresents a nitrogen-containing functional group.

M represents a transition metal of Groups 8 to 10 of the Periodic Table,concretely including Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt. Of these,preferred is Fe or Co.

R¹, R², R³ and R⁴ each independently represent a hydrogen atom, ahydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total. Thehydrocarbon group having from 1 to 20 carbon atoms includes a linearhydrocarbon group having from 1 to 20 carbon atoms, a branchedhydrocarbon group having from 3 to 20 carbon atoms, and a cycloaliphatichydrocarbon group having from 3 to 20 carbon atoms. Concretely, itincludes a methyl group, an ethyl group, an n-propyl group, an isopropylgroup, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butylgroup, a pentyl group, a hexyl group, an octyl group, a decyl group, atetradecyl group, a hexadecyl group, an octadecyl group, a cyclopentylgroup, a cyclohexyl group, a cyclooctyl group, etc.

X represents a halogen atom, and Y represents a hydrogen atom, a halogenatom, or a hydrocarbon group having from 1 to 20 carbon atoms. Thehydrocarbon group having from 1 to 20 carbon atoms may be the same asthat mentioned above. The halogen atom includes a chlorine atom, abromine atom, a fluorine atom, and an iodine atom, and is preferably achlorine atom. For the hydrocarbon group having from 1 to 20 carbonatoms, preferred is a methyl group.

Z is a nitrogen-containing functional group. Preferably, it isrepresented by the following general formula (I-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or a cycloaromatic hydrocarbongroup having from 7 to 20 carbon atoms in total; n represents 0 or anatural number.

The aliphatic hydrocarbon group having from 1 to 20 carbon atoms and thecycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal for R⁵ and R⁶may be the same as the hydrocarbon group having from1 to 20 carbon atoms and the cycloaromatic hydrocarbon group having from7 to 20 carbon atoms in total mentioned hereinabove for R¹, R², R³ andR⁴. n indicates 0 or a natural number, but is preferably any of 0, 1, 2or 3.

Specific examples of the nitrogen-containing compounds of formula (I-II)are

For Z, also preferred is a nitrogen-containing functional group of thefollowing general formula (I-III):

wherein R⁷, R⁸ and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total, and thesemay be bonded to each other to form a ring; n represents 0 or a naturalnumber.

The aliphatic hydrocarbon group having from 1 to 20 carbon atoms and thecycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal for R⁷, R⁸ and R⁹ may be the same as the hydrocarbon group havingfrom 1 to 20 carbon atoms and the cycloaromatic hydrocarbon group havingfrom 7 to 20 carbon atoms in total mentioned hereinabove for R¹, R², R³and R⁴. R⁷, R⁸ and R⁹ may be bonded to each other to form a ring. Thering is not specifically defined, including, for example, a cyclohexylskeleton, a cyclopentyl skeleton, etc. n indicates 0 or a naturalnumber, but is preferably any of 0, 1, 2 or 3.

Specific examples of the nitrogen-containing compounds of formula(I-III) are

For Z, especially preferred is the nitrogen-containing functional groupof formula (I-II) having a pyridine skeleton.

One preferred embodiment of the transition metal compound of formula(I-I) is represented by the following general formula (I-IV):

wherein M represents Fe or Co; X represents a halogen atom; Y representsa hydrogen atom, a halogen atom, or a hydrocarbon group having from 1 to20 carbon atoms.

Specific examples of the transition metal compound of that type are thefollowing compounds [3] to [15].

In the invention, one or more of the transition metal compoundsmentioned above may be used, either singly or as combined, for thecomponent (A).

(B) Clay, Clay Mineral or Ion-exchanging Layered Compound

For the component (B), used is any of clay, clay minerals orion-exchanging layered compounds.

Clay is an aggregate of fine hydrous silicate minerals. It is plasticwhen kneaded with a suitable amount of water, and is rigid when dried.When baked at high temperatures, it is sintered. Clay minerals arehydrous silicates which are the essential components constituting clay.

These are not limited to only natural ones, but synthetic products ofthose substances are employable herein.

Ion-exchanging layered compounds are characterized by their crystalstructure of such that a plurality of crystal planes formed throughionic bonding or the like are laminated in parallel layers via weakbonding force between the adjacent layers, in which the ions areexchangeable. Some clay minerals are ion-exchanging layered compounds.

For example, phyllosilicic acid compounds belong to clay minerals.Phyllosilicic acid compounds include phyllosilicic acid andphyllosilicates. As natural phyllosilicates, known are montmorillonite,saponite and hectorite of the smectite family; illite and sericite ofthe mica family; and mixed layer minerals of smectites and micas, orthose of micas and vermiculites.

As synthetic products, known are fluoro-tetrasilicon mica, laponite,smectone, etc.

Also mentioned are ionic crystalline compounds having a layered crystalstructure, such as α-Zr (HPO₄)₂, γ-Zr(HPO₄)₂, α-Ti(HPO₄)₂, γ-Ti(HPO₄)₂,etc. These are not clay minerals.

Examples of clay and clay minerals which do not belong to ion-exchanginglayered compounds and which are usable for the component (B) includeclay having a low montmorillonite content and referred to as bentonite;kibushi clay comprising montmorillonite and many other components;gairome clay; sepiolite and palygorskite having a fibrous morphology;and amorphous or low-crystalline allophane, imogolite, etc.

In the invention, the component (B) is contacted with the components (A)and (C), and it is desirable that clay, clay minerals and ion-exchanginglayered compounds for the component (B) are chemically treated for thepurpose of removing impurities from them or for modifying theirstructures and functions.

The chemical treatment referred to herein indicates both the surfacetreatment to remove impurities from surfaces and the treatment to modifythe crystal structure of clay. Concretely, it includes acid treatment,alkali treatment, salt treatment, organic treatment, etc.

The acid treatment is to remove impurities from surfaces, whilereleasing cations such as aluminium, iron, magnesium and the like fromcrystal structures to thereby enlarge surface areas. The alkalitreatment is to destroy the crystal structure of clay, thereby modifyingthe structure of clay. The salt treatment and the organic treatment areto form ionic complexes, molecular complexes, organic complexes, etc.,whereby surface areas and layer-to-layer spaces may be changed. Owing totheir ion-exchanging ability, the interlayer exchangeable ions in thecompounds may be exchanged with any other bulky ions to give layeredsubstances having enlarged interlayer spaces.

The substances for the component (B) noted above may be directly used asthey are, or, if desired, additional water may be adsorbed onto them, orthey may be heated and dehydrated prior to being used.

For the component (B), preferred are clay and clay minerals. Mostpreferred are phyllosilicic acid compounds, of which smectite isdesirable, and montmorillonite is more desirable.

(C) Organosilane Compound

Organosilane compounds for the component (C) in the invention include,for example, trialkylsilyl chlorides such as trimethylsilyl chloride,triethylsilyl chloride, triisopropylsilyl chloride,tert-butyldimethylsilyl chloride, tert-butyldiphenylsilyl chloride,phenethyldimethylsilyl chloride, etc.; dialkylsilyl dichlorides such asdimethylsilyl dichloride, diethylsilyl dichloride, diisopropylsilyldichloride, bisdiphenethylsilyl dichloride, methylphenethylsilyldichloride, diphenylsilyl dichloride, dimethylsilyl dichloride,ditolylsilyl dichloride, etc.; alkylsilyl trichlorides such asmethylsilyl trichloride, ethylsilyl trichloride, isopropylsilyltrichloride, phenylsilyl trichloride, mesitylsilyl trichloride,tolylsilyl trichloride, phenethylsilyl trichloride, etc.; other halidesto be derived from the compounds noted above by substituting thechloride moiety with any other halogens; silylamines such asbis(trimethylsilyl)amine, bis(triethylsilyl)amine,bis(triisopropylsilyl)amine, bis(dimethylethylsilyl) amine,bis(diethylmethylsilyl) amine, bis(dimethylphenylsilyl)amine,bis(dimethyltolylsilyl)amine, bis(dimethylmesitylsilyl)amine,N,N-dimethylaminotrimethylsilane, (diethylamino) trimethylsilane,N-(trimethylsilyl)imidazole, etc.; polysilanols generally referred to asperalkylpolysiloxypolyols; silanols such astris(trimethylsiloxy)silanol, etc.; silylamides such asN,O-bis(trimethylsilyl)acetamide, bis(trimethylsilyl)trifluoroacetamide,N-(trimethylsilyl)acetamide, bis(trimethylsilyl)urea,trimethylsilyldiphenylurea, etc.; linear siloxanes such as1,3-dichlorotetramethyldisiloxane, etc.; cyclic siloxanes such aspentamethylcyclopentanesiloxane, etc.; tetraalkylsilanes such asdimethyldiphenylsilane, diethyldiphenylsilane,diisopropyldiphenylsilane, etc.; and trialkylsilanes such astrimethylsilane, triethylsilane, triisopropylsilane, tri-t-butylsilane,triphenylsilane, tritolylsilane, trimesitylsilane, methyldiphenylsilane,dinaphthylmethylsilane, bis(diphenyl)methylsilane, etc. Of those,preferred are organosilane compounds having at least one alkyl groupdirectly bonded to the silicon atom. More preferred are alkylsilylhalides, and even more preferred are dialkylsilyl halides. One of thosecompounds may be used for the component (C). As the case may be,however, two or more of the compounds may be used, as combined in anydesired manner.

(D) Organoaluminium Compound

In the invention, (D) an organoaluminium compound and/or (E) analkylating agent are/is used.

Organoaluminium compounds for the component (D) are not specificallydefined. For example, preferred are alkyl group-having aluminiumcompounds of the following general formula (I-V):

R¹⁴ _(p)Al(OR¹⁵)_(q)L₃-p-q  (I-V)

wherein R¹⁴ and R¹⁵ each represent a hydrogen atom, or a hydrocarbongroup having from 1 to 20, preferably from 1 to 4 carbon atoms; Lrepresents a halogen atom; 0<p≦3, preferably p=2 or 3, most preferablyp=3; 0≦q<3, preferably q=0 or 1.

Examples of the compounds are trialkylaluminiums such astrimethylaluminium, triethylaluminium, tripropylaluminium,triisobutylaluminium, tri-t-butylaluminium, etc.; halogen-, alkoxy- orhydroxyl-having alkylaluminiums such as dimethylaluminium chloride,diethylaluminium chloride, dimethylaluminium methoxide, diethylaluminiummethoxide, dimethylaluminium hydroxide, diethylaluminium hydroxide,etc.; hydrogen-having alkylaluminiums such as dimethylaluminium hydride,diisobutylaluminium hydride, etc. Of those, preferred aretrialkylaluminiums, and more preferred are trimethylaluminium andtriisobutylaluminium. One or more of the organoaluminium compoundsmentioned above may be used herein either singly or as combined.

(E) Alkylating Agent

In the invention, optionally used is an alkylating agent for thecomponent (E). Various types of alkylating agents are usable herein. Forexample, they include alkyl group-having aluminium compounds of theabove-mentioned general formula (I-V), alkyl group-having magnesiumcompounds of the following general formula (I-VI), and alkylgroup-having zinc compounds of the following general formula (I-VII):

R¹⁶ ₂Mg  (I-VI)

wherein R¹⁶'s each represent a hydrocarbon group having from 1 to 20,preferably from 1 to 3 carbon atoms, and they may be the same ordifferent,

R¹⁶ ₂Zn  (I-VII)

wherein R¹⁶ has the same meaning as above.

Of these alkyl group-having compounds, preferred are alkyl group-havingaluminium compounds, and more preferred are trialkylaluminiums anddialkylaluminiums. Concretely, they include trialkylaluminiums such astrimethylaluminium, triethylaluminium, tri-n-propylaluminium,tri-n-butylaluminium, triisobutylaluminium, tri-t-butylaluminium, etc.;dialkylaluminium halides such as dimethylaluminium chloride,diethylaluminium chloride, di-n-butylaluminium chloride,diisobutylaluminium chloride, di-t-butylaluminium chloride, etc.;dialkylaluminium alkoxides such as dimethylaluminium methoxide,dimethylaluminium ethoxide, etc.; dialkylaluminium hydrides such asdimethylaluminium hydride, diethylaluminium hydride, diisobutylaluminiumhydride, etc. They further include dialkylmagnesiums such asdimethylmagnesium, diethylmagnesium, di-n-propylmagnesium,diisopropylmagnesium, dibutylmagnesium, etc.; and dialkylzincs such asdimethylzinc, diethylzinc, ethyl-n-propylzinc, diisopropylzinc, etc. Ofthese, alkyl group-having aluminium compounds of formula (I-V) arepreferred for the component (E). More preferred are trialkylaluminiums.

In the invention, one or more of the compounds mentioned above may beused, either singly or as combined, for the component (E).

The ratio of the components constituting the catalyst of the inventionis not specifically defined. In case where the component (B) is clay ora clay mineral, the blend ratio of the component (B) in terms of thehydroxyl group therein to mol of the transition metal in the component(A) may fall generally between 0.1 and 100000 mols, but preferablybetween 0.5 and 10000 mols; that of the component (C) in terms of thesilicon atom therein may fall generally between 0.1 and 100000 mols, butpreferably between 0.5 and 10000 mols; and that of the organoaluminiumcompound of the component (D) in terms of the aluminium atom therein mayfall generally between 0.1 and 100000 mols, but preferably between 0.5and 10000 mols. In case where the component (B) is any other than clayor clay minerals, the blend ratio of the component (A) in terms of thetransition metal therein to gram of the component (B) preferably fallsbetween 0.00001 and 1 g; and that of the component; (C) in terms of thesilicon atom therein preferably falls between 0.001 and 100 g. Alsopreferably, the blend ratio of the component (E) in terms of thealuminium, magnesium or zinc atom therein falls between 1 and 10000mols. If the blend ratios of the constituent components oversteps thedefined ranges, the polymerization activity of the catalyst will be low.

The mode of preparing the polymerization catalyst is not specificallydefined, and various methods are employable for preparing it.

For example, in case where the components (A), (B), (C) and (D) are usedfor preparing the catalyst, the component (A) and the component (B) arefirst contacted with each other, and thereafter the component (C) andthe component (D) are added thereto; or the component (A) is firstcontacted with the component (C) and the component (D), and thereafterthe component (B) is added thereto; or the component (B) is firstcontacted with the component (C) and the component (D), and thereafterthe component (A) is added thereto; or the four components are contactedwith each other all at a time.

Of those, preferred is the method of first contacting the component (B)with the component (C) and the component (D) followed by adding thecomponent (A) thereto.

In case where the component (E) is used for preparing the catalyst, theorder of adding the component (E) to the other components is notspecifically defined. Irrespective of the presence or absence of thecomponent (D), it is desirable that the constituent components arecontacted with each other in any of the four methods mentioned above andthereafter the component (E) is added thereto and contacted with them ina polymerization system. In the invention, while or after theconstituent components are contacted with each other, a polymer such aspolyethylene, polypropylene or the like, or an inorganic oxide such assilica, alumina or the like may be present in the system or may becontacted with the components.

Contacting the components with each other may be effected in an inertgas such as nitrogen or the like, or in a hydrocarbon such as pentane,hexane, heptane, toluene, xylene or the like. Contacting the componentswith each other or adding them to the polymerization system may beeffected at the polymerization temperature or even at a temperaturefalling between −30° C. and the boiling point of the solvent used, butpreferably between room temperature and the boiling point of thesolvent.

[2] Method for Producing Olefin Polymers

In the method for producing polyolefins in the invention, favorably usedis the catalyst noted above for homopolymerization of olefins or forcopolymerization of olefins with other olefins and/or other monomers(that is, copolymerization of different types of olefins, orcopolymerization of olefins with other monomers, or copolymerization ofdifferent types of olefins with other monomers).

Olefins to be polymerized in the invention are not specifically defined,but preferred are α-olefins having from 2 to 20 carbon atoms. α-olefinsof that type include, for example, ethylene, propylene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,4-phenyl-1-butene, 6-phenyl-1-hexene, 3-methyl-1-butene,4-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-hexene,5-methyl-1-hexene, 3,3-dimethyl-1-pentene, 3,4-dimethyl-1-pentene,4,4-dimethyl-1-pentene, vinylcyclohexane, etc. Other olefins includedienes such as 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, etc.;halogen-substituted α-olefins such as hexafluoropropene,tetrafluoroethylene, 2-fluoropropene, fluoroethylene,1,1-difluoroethylene, 3-fluoropropene, trifluoroethylene,3,4-dichloro-1-butene, etc.; cyclic olefins such as cyclopentene,cyclohexene, norbornene, 5-methylnorbornene, 5-ethylnorbornene,5-propylnorbornene, 5,6-dimethylnorbornene, 5-benzylnorbornene, etc.Styrenic compounds usable herein include, for example, styrene;alkylstyrenes such as p-methylstyrene, p-ethylstyrene, p-propylstyrene,p-isopropylstyrene, p-butylstyrene, p-tert-butylstyrene,p-phenylstyrene, o-methylstyrene, o-ethylstyrene, o-propylstyrene,o-isopropylstyrene, m-methylstyrene, m-ethylstyrene, m-isopropylstyrene,m-butylstyrene, mesitylstyrene, 2,4-dimethylstyrene,2,5-dimethylstyrene, 3,5-dimethylstyrene, etc.; alkoxystyrenes such asp-methoxystyrene, o-methoxystyrene, m-methoxystyrene, etc.;halogenostyrenes such as p-chlorostyrene, m-chlorostyrene,o-chlorostyrene, p-bromostyrene, m-bromostyrene, o-bromostyrene,p-fluorostyrene, m-fluorostyrene, o-fluorostyrene,o-methyl-p-fluorostyrene, etc.; and also trimethylsilylstyrene,vinylbenzoates, divinylbenzene, etc. The other olefins to becopolymerized may be suitably selected from the olefins mentioned above.

In the invention, one or more olefins such as those mentioned above maybe homopolymerized or copolymerized either singly or as combined. Wheretwo or more different olefins are copolymerized, the olefins mentionedabove may be combined in any desired manner.

In the invention, olefins such as those mentioned above may becopolymerized with any other comonomers. The comonomers include, forexample, linear diolefins such as butadiene, isoprene, 1,4-pentadiene,1,5-hexadiene, etc.; polycyclic olefins such as norbornene,1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-norbornene,etc.; cyclic diolefins such as norbornadiene, 5-ethylidenenorbornene,5-vinylnorbornene, dicyclopentadiene, etc.; and unsaturated esters suchas ethyl acrylate, methyl methacrylate, etc.

Of olefins such as those mentioned above, ethylene is especiallypreferred in the invention. The method for polymerizing olefins is notspecifically defined and may be any ordinary one including, for example,slurry polymerization, solution polymerization, vapor-phasepolymerization, bulk polymerization, suspension polymerization, etc.

A polymerization solvent may be used in the invention. It includeshydrocarbons and halogenohydrocarbons such as benzene, toluene, xylene,n-hexane, n-heptane, cyclohexane, methylene chloride, chloroform,1,2-dichloroethane, chlorobenzene, etc. One or more of such solvents areusable either singly or as combined. Depending on their type, monomersto be polymerized may also serve as solvents.

In view of the catalytic activity for polymerization and of the reactorefficiency, it is desirable that the amount of the catalyst to be in thepolymerization system is so controlled that the amount of the component(A) could fall generally between 0.5 and 100 μmols, but preferablybetween 2 and 25 μmols, in one liter of the solvent in the system.

Regarding the polymerization condition, the pressure may fall generallybetween ordinary pressure and 2000 kg/cm²G. The reaction temperature mayfall generally between −50 and 250° C. For controlling the molecularweight of the polymers to be produced, the type and the amount of thecatalytic components to be used and the polymerization temperature willbe suitably selected. If desired, hydrogen may be introduced into thepolymerization system for that purpose.

The invention is described in more detail with reference to thefollowing Examples, which, however, are not intended to restrict thescope of the invention.

EXAMPLE I-1

(1) Chemical Treatment of Clay Mineral

40 g of a commercial product of montmorillonite (Kunipia F from KunimineIndustry) was ground in a grinder for 4 hours. 20 g of the powderedmontmorillonite was put into a four-necked flask having a capacity of500 ml, and dispersed in 100 ml of deionized water containing 20 g ofmagnesium chloride 6-hydrate dissolved therein. This was stirred at 90°C. for 0.5 hours. After having been thus processed, the solid residuewas washed with water. This treatment was repeated once again. Thus wasobtained magnesium chloride-processed montmorillonite. This was dried,then dispersed in 160 ml of an aqueous solution of 6% HCl, and stirredunder reflux for 2 hours. After having been thus processed, this waswashed with water through repeated filtration until the filtration washbecame neutral, and then dried. The product thus obtained ischemical-treated montmorillonite.

(2) Contact Treatment with Silane Compound and Organoaluminium

1.0 g of the chemical-treated montmorillonite obtained in (1) (this hada water content of 15% by weight—the water content is derived from theweight loss obtained by dewatering its sample under heat at 150° C. for1 hour, and the same shall apply hereunder) was put into a 300 mlSchlenk tube, to which was added 25 ml of toluene. These were dispersedto prepare a slurry. To this was added 1.13 g (5.2 mmols) ofphenethylmethylsilyl dichloride, and stirred at room temperature for 60hours and then under heat at 100° C. for 1 hour. This was cooled to roomtemperature, the resulting supernatant was removed, and the solidresidue was washed with 200 ml of toluene. Next, 12.5 mmols oftriisobutylaluminium was added thereto, and then stirred at roomtemperature for 30 minutes. Stirring it was stopped, and the solidresidue was washed with 200 ml of toluene. Toluene was added to theresulting slurry to make a total volume of 50 ml. The clay mineralsolution thus obtained was analyzed through IPC, through which thetriisobutylaluminium-derived Al content of the clay mineral was found tobe 1.4 mmols (of Al atom)/g.

(3) Polymerization of Ethylene

An autoclave having a capacity of 1.6 liters was fully dried and thenpurged with nitrogen. 400 ml of toluene having been dewatered at roomtemperature, 25 μmols of trimethylaluminium, 5 ml of the clay mineralsolution having been prepared in (2) (corresponding to 0.1 g of the claymineral, and having an Al content of 0.14 mmols), and 5 μmols of theiron complex [3] mentioned above (this is a transition metal compoundhaving a nitrogen-containing tridentate ligand) were put into theautoclave in that order. Ethylene was continuously introduced into theautoclave at 25° C. to have a pressure of 8 kg/cm²G therein, andpolymerized for 30 minutes. Next, methanol was added to this to stop thepolymerization. The polymer thus produced was taken out throughfiltration, and dried at 90° C. under reduced pressure for 12 hours. Thepolymer thus obtained weighed 73.8 g. The polymerization activity of thecatalyst used herein was 503 kg/g-Fe·hr.

The polymer had an intrinsic viscosity [η] of 3.94 dl/g measured indecalin at 135° C., and had a density of 0.9332 g/cm³.

EXAMPLE I-2

(1) Chemical Treatment of Clay Mineral

This is the same as in (1) in Example I-1.

(2) Contact Treatment with Silane Compound and Organoaluminium

This is the same as in (2) in Example I-1.

(3) Polymerization of Ethylene

This is the same as in Example I-1, except that triisobutylaluminium andnot trimethylaluminium was used herein. The polymer obtained weighed68.1 g. (The polymerization activity of the catalyst used was 464kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 8.95 dl/g measured indecalin at 135° C., and had a density of 0.9361 g/cm³.

EXAMPLE I-3

(1) Chemical Treatment of Clay Mineral

This is the same as in (1) in Example I-1.

(2) Contact Treatment with Silane Compound and Organoaluminium

This is the same as in (2) in Example I-1.

(3) Polymerization of Ethylene

This is the same as in Example I-1. In this, however, the iron complex[4] mentioned above and not [3] was used and trimethylaluminium was notused. The polymer obtained weighed 70.2 g. (the polymerization activityof the catalyst used was 478 kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 3.86 dl/g measured indecalin at 135° C., and had a density of 0.9342 g/cm³.

EXAMPLE I-4

(1) Chemical Treatment of Clay Mineral

This is the same as in (1) in Example I-1.

(2) Contact Treatment with Silane Compound

This is the same as in (2) in Example I-1. In this, however, the claymineral was not processed with triisobutylaluminium.

(3) Polymerization of Ethylene

An autoclave having a capacity of 1.6 liters was fully dried and thenpurged with nitrogen. 400 ml of toluene having been dewatered at roomtemperature, 25 μmols of trimethylaluminium, 5 ml of the clay mineralsolution having been prepared in (2) (corresponding to 0.1 g of the claymineral), and 5 μmols of the iron complex [3] mentioned above (this is atransition metal compound having a nitrogen-containing tridentateligand) were put into the autoclave in that order. Ethylene wascontinuously introduced into the autoclave at 25° C. to have a pressureof 8 kg/cm²G therein, and polymerized for 30 minutes. Next, methanol wasadded to this to stop the polymerization. The polymer thus produced wastaken out through filtration, and dried at 90° C. under reduced pressurefor 12 hours. The polymer thus obtained weighed 62.5 g. Thepolymerization activity of the catalyst used herein was 426 kg/g-Fe·hr.

The polymer had an intrinsic viscosity [η] of 4.53 dl/g measured indecalin at 135° C., and had a density of 0.9368 g/cm³.

EXAMPLE I-5

(1) Chemical Treatment of Clay Mineral

This is the same as in (1) in Example I-1.

(2) Contact Treatment with Silane Compound

This is the same as in (2) in Example I-4.

(3) Polymerization of Ethylene

This is the same as in Example I-4, except that triisobutylaluminium andnot trimethylaluminium was used herein. The polymer obtained weighed65.8 g. (The polymerization activity of the catalyst used was 448kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 8.87 dl/g measured indecalin at 135° C., and had a density of 0.9335 g/cm³

Comparative Example I-1

The same process as in Example I-1 was repeated, except that 1 mmol ofmethylaluminoxane and not the clay mineral solution prepared in (2) inExample I-1 was used as a promoter. The polymer obtained weighed 54.1 g.(The polymerization activity of the catalyst used was 369 kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 3.6 dl/g, and a density of0.9303 g/cm³.

Comparative EXAMPLE I-2

The same process as in Example I-1 was repeated, except that 165 μmolsof methylaluminoxane and not the clay mineral solution prepared in (2)in Example I-1 was used as a promoter. The polymer obtained weighed 20.2g. (The polymerization activity of the catalyst used was 173kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 1.23 dl/g, and a densityof 0.9324 g/cm³.

Second Aspect of the Invention

As so mentioned above, the catalyst for olefin polymerization of thesecond aspect of the invention (in this section, the second aspect ofthe invention will be simply referred to as “the invention”) comprises(A) a transition metal compound which has a nitrogen-containingtridentate ligand and of which the transition metal is of Groups 8 to 10of the Periodic Table, (B) clay, a clay mineral or an ion-exchanginglayered compound and (C) an organosilane compound. In the method forproducing olefin polymers of the invention, the olefin polymerizationcatalyst is used for polymerizing olefins.

The catalyst for olefin polymerization and the method for producingolefin polymers of the invention are described in detail hereinunder.

[1] Catalyst for Olefin Polymerization

(1) Transition Metal Compound (A)

The transition metal compound (A) for use in the invention, which has anitrogen-containing tridentate ligand and of which the transition metalis of Groups 8 to 10 of the Periodic Table, is not specifically defined,but is preferably represented by the following general formula (II-I):

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent ahydrogen atom, a hydrocarbon group having from 1 to 20 carbon atoms, ora cycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal; X and Y each independently represent a hydrogen atom, or ahydrocarbon group having from 1 to 20 carbon atoms; Z represents anitrogen-containing functional group.

M represents a transition metal of Groups 8 to 10 of the Periodic Table,concretely including Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt. Of these,preferred is Fe or Co.

R¹, R², R³ and R⁴ each independently represent a hydrogen atom, ahydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total. Thehydrocarbon group having from 1 to 20 carbon atoms includes a linearhydrocarbon group having from 1 to 20 carbon atoms, a branchedhydrocarbon group having from 3 to 20 carbon atoms, and a cycloaliphatichydrocarbon group having from 3 to 20 carbon atoms. Concretely, itincludes a methyl group, an ethyl group, an n-propyl group, an isopropylgroup, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butylgroup, a pentyl group, a hexyl group, an octyl group, a decyl group, atetradecyl group, a hexadecyl group, an octadecyl group, a cyclopentylgroup, a cyclohexyl group, a cyclooctyl group, etc.

X and Y each indicate a hydrogen atom, or a hydrocarbon group havingfrom 1 to 20 carbon atoms. The hydrocarbon group having from 1 to 20carbon atoms may be the same as that mentioned hereinabove. For this,preferred is a methyl group. X and Y may be the same or different.

Z is a nitrogen-containing functional group. Preferably, it isrepresented by the following general formula (II-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or a cycloaromatic hydrocarbongroup having from 7 to 20 carbon atoms in total; n represents 0 or anatural number.

The aliphatic hydrocarbon group having from 1 to 20 carbon atoms and thecycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal for R⁵ and R⁶ may be the same as the hydrocarbon group having from1 to 20 carbon atoms and the cycloaromatic hydrocarbon group having from7 to 20 carbon atoms in total mentioned hereinabove for R¹, R², R³ andR⁴. n indicates 0 or a natural number, but is preferably any of 0, 1, 2or 3.

Specific examples of the nitrogen-containing functional groups offormula (II-II) are

For Z, also preferred is a nitrogen-containing functional group of thefollowing general formula (II-III):

wherein R⁷, R⁸ and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or a cycloaromatichydrocarbon group having from 7 to 20 carbon atoms in total, and thesemay be bonded to each other to form a ring; n represents 0 or a naturalnumber.

The aliphatic hydrocarbon group having from 1 to 20 carbon atoms and thecycloaromatic hydrocarbon group having from 7 to 20 carbon atoms intotal for R⁷, R⁸ and R⁹ may be the same as the hydrocarbon group havingfrom 1 to 20 carbon atoms and the cycloaromatic hydrocarbon group havingfrom 7 to 20 carbon atoms in total mentioned hereinabove for R¹, R², R³and R⁴. n indicates 0 or a natural number, but is preferably any of 0,1, 2 or 3.

R⁷, R⁸ and R⁹ may be bonded to each other to form a ring.

Specific examples of the nitrogen-containing functional groups offormula (II-III) are

For Z, especially preferred is the nitrogen-containing functional groupof formula (II-II) having a pyridine skeleton.

One preferred embodiment of the transition metal compound of formula(II-I) is represented by the following general formula:

wherein M represents Fe or Co; X and Y each independently represent ahydrogen atom, or a hydrocarbon group having from 1 to 20 carbon atoms.

Specific examples of the transition metal compound of that type are thefollowing compounds [3] to [11].

In the invention, one or more of the transition metal compoundsmentioned above may be used, either singly or as combined,: for thecomponent (A).

(B) Component (B)

For the component (B), used is any of clay, clay minerals orion-exchanging layered compounds. For their details and examples,referred to is the description relating to them in the section of thefirst aspect of the invention mentioned above. All those mentioned inthe first section shall apply also to this section.

(C) Organosilane Compound

In the invention, used is an organosilane compound for the component(C). For its details and examples, referred to is the descriptionrelating to it in the section of the first aspect of the inventionmentioned above. All those mentioned in the first section shall applyalso to this section.

(D) Organoaluminium Compound

In the invention, optionally used is the organoaluminium compound (D).For its details and examples, referred to is the description relating toit in the section of the first aspect of the invention mentioned above.All those mentioned in the first section shall apply also to thissection. In view of its polymerization activity, the catalyst preferablycontains the component (D).

The ratio of the components constituting the catalyst of the inventionis not specifically defined. In case where the component (B) is clay ora clay mineral, the blend ratio of the component (B) in terms of thehydroxyl group therein to mol of the transition metal in the component(A) may fall generally between 0.1 and 100000 mols, but preferablybetween 0.5 and 10000 mols; that of the component (C) in terms of thesilicon atom therein may fall generally between 0.1 and 100000 mols, butpreferably between 0.5 and 10000 mols; and that of the organoaluminiumcompound of the component (D) in terms of the aluminium atom therein mayfall generally between 0.1 and 100000 mols, but preferably between 0.5and 10000 mols. In case where the component (B) is any other than clayor clay minerals, the blend ratio of the component (A) in terms of thetransition metal therein to gram of the component (B) preferably fallsbetween 0.00001 and 1 g; and that of the component (C) in terms of thesilicon atom therein preferably falls between 0.001 and 100 g. Alsopreferably, the blend ratio of the component (D) in terms of thealuminium atom therein falls between 1 and 10000 mols.

The mode of preparing the polymerization catalyst is not specificallydefined, and various methods are employable for preparing it.

For example, the component (A) and the component (B) are first contactedwith each other, and thereafter the component (C) is added thereto; orthe component (A) is first contacted with the component (C), andthereafter the component (B) is added thereto; or the component (B) isfirst contacted with the component (C), and thereafter the component (A)is added thereto; or the three components are contacted with each otherall at a time. Of those, preferred is the method of first contacting thecomponent (B) with the component (C) followed by adding the component(A) thereto.

In case where the component (D) is used for preparing the catalyst, itmay be contacted with the other components in any desired order with nolimitation in the four methods mentioned above. It may be present in thesystem in the first stage of reaction, or may be added to the systemafter the other components have been contacted with each other.

In the invention, while or after the catalytic components are contactedwith each other, a polymer such as polyethylene, polypropylene or thelike, or a solid inorganic oxide such as silica, alumina or the like maybe present in the system or may be contacted with the components.Contacting the components with each other may be effected in an inertgas such as nitrogen or the like, or in a hydrocarbon such as pentane,hexane, heptane, toluene, xylene or the like. Contacting the componentswith each other or adding them to the polymerization system may beeffected at the polymerization temperature or even at a temperaturefalling between −30° C. and the boiling point of the solvent used, butpreferably between room temperature and the boiling point of thesolvent.

[2] Method for Producing Olefin Polymers

The method for producing olefin polymers of the invention ischaracterized by homopolymerizing or copolymerizing olefins in thepresence of the catalyst that comprises the component (A), a transitionmetal compound, the component (B), any of clay, clay minerals orion-exchanging layered compound, and the component (C), an organosilanecompound.

In the method for producing polyolefins in the invention, favorably usedis the catalyst noted above for homopolymerization of olefins or forcopolymerization of olefins with other olefins and/or other monomers(that is, copolymerization of different types of olefins, orcopolymerization of olefins with other monomers, or copolymerization ofdifferent types of olefins with other monomers).

Olefins to be polymerized in the invention are not specifically defined.For their examples, referred to is the description relating to them inthe first aspect of the invention mentioned above. All those mentionedin the first section shall apply also to this section.

In the invention, one or more olefins such as those mentioned above maybe homopolymerized or copolymerized either singly or as combined. Wheretwo or more different olefins are copolymerized, the olefins mentionedabove may be combined in any desired manner.

In the invention, olefins such as those mentioned above may becopolymerized with any other comonomers. For the comonomers, all thoseconcretely mentioned in the first aspect of the invention shall applyalso to this section.

Of olefins such as those mentioned above, ethylene is especiallypreferred in the invention. The method for polymerizing olefins is notspecifically defined and may be any ordinary one including, for example,slurry polymerization, solution polymerization, vapor-phasepolymerization, bulk polymerization, suspension polymerization, etc.

A polymerization solvent may be used in the invention. It includeshydrocarbons and halogenohydrocarbons such as benzene, toluene, xylene,n-hexane, n-heptane, cyclohexane, methylene chloride, chloroform,1,2-dichloroethane, chlorobenzene, etc. One or more of such solvents areusable either singly or as combined. Depending on their type, monomersto be polymerized may also serve as solvents.

In view of the catalytic activity for polymerization and of the reactorefficiency, it is desirable that the amount of the catalyst to be in thepolymerization system is so controlled that the amount of the component(A) could fall generally between 0.5 and 100 μmols, but preferablybetween 2 and 25 μmols, in one liter of the solvent in the system.

Regarding the polymerization condition, the pressure may fall generallybetween ordinary pressure and 2000 kg/cm²G. The reaction temperature mayfall generally between −50 and 250° C. For controlling the molecularweight of the polymers to be produced, the type and the amount of thecatalytic components to be used and the polymerization temperature willbe suitably selected. If desired, hydrogen may be introduced into thepolymerization system for that purpose.

The invention is described in more detail with reference to thefollowing Examples, which, however, are not intended to restrict thescope of the invention.

EXAMPLE II-1

(1) Chemical Treatment of Clay Mineral

40 g of a commercial product of montmorillonite (Kunipia F from KunimineIndustry) was ground in a grinder for 4 hours. 20 g of the powderedmontmorillonite was put into a four-necked flask having a capacity of500 ml, and dispersed in 100 ml of deionized water containing 20 g ofmagnesium chloride 6-hydrate dissolved therein. This was stirred at 90°C. for 0.5 hours. After having been thus processed, the solid residuewas washed with water. This treatment was repeated once again. Thus wasobtained magnesium chloride-processed montmorillonite. This was dried,then dispersed in 160 ml of an aqueous solution of 6% HCl, and stirredunder reflux for 2 hours. After having been thus processed, this waswashed with water through repeated filtration until the filtration washbecame neutral, and then dried. The product thus obtained ischemical-treated montmorillonite.

(2) Contact Treatment of Clay Mineral with Organosilane Compound

1.0 g of the chemical-treated montmorillonite obtained in (1) (this hada water content of 15% by weight—the water content is derived from theweight loss obtained by dewatering its sample-under heat at 150° C. for1 hour) was put into a 300 ml Schlenk tube, to which was added 25 ml oftoluene. These were dispersed to prepare a slurry. To this was added1.13 g (5.2 mmols) of phenethylmethylsilyl dichloride, and stirred atroom temperature for 60 hours and then under heat at 100° C. for 1 hour.This was cooled to room temperature, the resulting supernatant wasremoved, and the solid residue was washed with 200 ml of toluene.Toluene was added to the resulting slurry to make a total volume of 50ml. Thus was obtained a solution of the clay mineral.

(3) Polymerization of Ethylene

An autoclave having a capacity of 1.6 liters was fully dried and thenpurged with nitrogen. 400 ml of toluene having been dewatered at roomtemperature, 5 ml of the clay mineral solution having been prepared in(2) (corresponding to 0.1 g of the clay mineral), and 5 μmols of thecompound [3] mentioned above (this is a compound of a transition metalof Groups 8 to 10 of the Periodic Table, having a nitrogen-containingtridentate ligand) were put into the autoclave in that order. Ethylenewas continuously introduced into the autoclave at 25° C. to have apressure of 8 kg/cm²G therein, and polymerized for 30 minutes. Next,methanol was added to this to stop the polymerization. The polymer thusproduced was taken out through filtration, and dried at 90° C. underreduced pressure for 12 hours. The polymer thus obtained weighed 62.2 g.The polymerization activity of the catalyst used herein was 423kg/g-Fe·hr.

The polymer had an intrinsic viscosity [η] of 4.2 dl/g measured indecalin at 135° C., and had a density of 0.9351 g/cm³. This wasgranular, having a bulk density of 0.35 g/cm³. The reactor used forpolymerization was checked, and no deposit adhered to its wall.

Comparative Example II-1

The same process as in Example II-1 was repeated, except that 1 mmol ofmethylaluminoxane and not the clay mineral solution prepared in (2) wasused as a promoter. The polymer obtained weighed 54.1 g. (Thepolymerization activity of the catalyst used was 369 kg/g-Fe·hr.)

The polymer had an intrinsic viscosity [η] of 3.6 dl/g, and a density of0.9303 g/cm³. This was bulky and amorphous. The reactor used forpolymerization was checked, and some deposit adhered to its wall.

From the above, it is understood that the polymerization activity of thecatalyst of the invention, though not containing an expensivealuminoxane or organoaluminium but containing a clay mineral, iscomparable to or higher than that of conventional catalysts. Inaddition, it is understood that, in the method where the catalyst of theinvention is used, no deposit adheres to the reactor wall and thepolymer produced has good powder morphology.

Industrial Applicability

Comprising a transition metal compound which has a nitrogen-containingtridentate ligand and of which the transition metal is of Groups 8 to 10of the Periodic Table, any of clay, a clay mineral or an ion-exchanginglayered compound, and an organosilane compound, and optionallycontaining, an organoaluminium compound and others, the catalyst of theinvention has high activity. In the method of using the catalyst forproducing polyolefins, no deposit adheres to the reactor wall and thepolyolefins produced have good powder morphology. The invention realizesefficient production of polyolefins (especially polyethylene) on anindustrial scale.

What is claimed is:
 1. A catalyst for olefin polymerization, comprising:(A) a transition metal compound of the following formula (I-I), whichhas a nitrogen-containing tridentate ligand and of which the transitionmetal is of Groups 8 to 10 of the agent:

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent hydrogen,a hydrocarbon group having from 1 to 20 carbon atoms, or an aromatichydrocarbon group having from 7 to 20 carbon atoms; X represents ahalogen atom; Y represents hydrogen, or a hydrocarbon group having from1 to 20 carbon atoms; and Z represents a nitrogen-containing functionalgroup.
 2. The catalyst for olefin polymerization as claimed in claim 1,in which X in formula (I-I) is represented by the following formula(I-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or an aromatic hydrocarbon grouphaving from 7 to 20 carbon atoms; and n represents 0 or a naturalnumber.
 3. The catalyst for olefin polymerization as claimed in claim 1,in which Z in formula (I-I) is represented by the following formula(I-III):

wherein R⁷, R⁸ and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or an aromatichydrocarbon group having from 7 to 20 carbon atoms, and these may bebonded to each other to form a ring; and n represents 0 or a naturalnumber.
 4. The catalyst for olefin polymerization as claimed in claim 1,in which the transition metal of Groups 8 to 10 of the Periodic Table isiron or cobalt.
 5. The catalyst for olefin polymerization as claimed inany of claims 1 to 4, in which (C) is an organosilane compound having atleast one alkyl group directly bonded to the silicon atom.
 6. Thecatalyst for olefin polymerization as claimed in claim 1, in which thealkylating agent is a trialkylaluminium compound.
 7. A catalyst forolefin polymerization, comprising (A) a transition metal compound whichhas a nitrogen-containing tridentate ligand and of which the transitionmetal is of Groups 8 to 10 of the Periodic Table, (B) clay, a claymineral or an ion-exchanging layered compound and (C) an organosilanecompound.
 8. The catalyst for olefin polymerization as claimed in claim7, in which the transition metal compound (A) is represented by thefollowing formula (II-I)

wherein M represents a transition metal of Groups 8 to 10 of thePeriodic Table; R¹, R², R³ and R⁴ each independently represent hydrogen,a hydrocarbon group having from 1 to 20 carbon atoms, or an aromatichydrocarbon group having from 7 to 20 carbon atoms; V and W eachindependently represent hydrogen, or a hydrocarbon group having from 1to 20 carbon atoms; and Z represents a nitrogen-containing functionalgroup.
 9. The catalyst for olefin polymerization as claimed in claim 8,in which Z in formula (II-I) is represented by the following formula(II-II):

wherein R⁵ and R⁶ each independently represent an aliphatic hydrocarbongroup having from 1 to 20 carbon atoms, or an aromatic hydrocarbon grouphaving from 7 to 20 carbon atoms; and n represents 0 or a naturalnumber.
 10. The catalyst for olefin polymerization as claimed in claim8, in which Z in formula (II-I) is represented by the following formula(II-III):

wherein R⁷, R⁸and R⁹ each independently represent an aliphatichydrocarbon group having from 1 to 20 carbon atoms, or an aromatichydrocarbon group having from 7 to 20 carbon atoms, and these may bebonded to each other to form a ring; and n represents 0 or a naturalnumber.
 11. The catalyst for olefin polymerization as claimed in any ofclaims 7 to 10, in which the transition metal of Groups 8 to 10 of thePeriodic Table is iron or cobalt.
 12. The catalyst for olefinpolymerization as claimed in any of claims 1 to 11, in which (B) is aphyllosilicate.
 13. The catalyst for olefin polymerization as claimed inany of claims 1 to 11, in which (B) is montmorillonite.
 14. A method forproducing olefin polymers, which comprises polymerizing olefins in thepresence of the catalyst for olefin polymerization of any of claims 1 to13.
 15. The method for producing olefin polymers as claimed in claim 14,in which the olefin is ethylene.